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United States Patent |
5,099,892
|
Siegenthaler
|
March 31, 1992
|
Process and apparatus for the manufacture of an automotive tire bead
Abstract
A method and apparatus for manufacturing an automotive tire bead (1),
whereby an annular element (2) having a substantially circular section and
consisting of a coiled metal wire (3) is formed by winding the wire (3)
about a mandrel (17) defining a duct (9) coiling about the annular element
(2). One end of a flexible packing member (5) of heat-shrinkable material
is then inserted inside duct (9), blown along the whole length of the
same, cut to size, and the two ends joined to form a loop.
Inventors:
|
Siegenthaler; Karl J. (Rome, IT)
|
Assignee:
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Bridgestone/Firestone, Inc. (Akron, OH)
|
Appl. No.:
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624437 |
Filed:
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December 7, 1990 |
Foreign Application Priority Data
| Dec 22, 1989[IT] | 68169 A/89 |
Current U.S. Class: |
140/88; 140/92.94; 245/1.5 |
Intern'l Class: |
B21F 037/00 |
Field of Search: |
100/12,13
245/1.5
140/88,92.94,101
156/136,422,457
|
References Cited
U.S. Patent Documents
464693 | Dec., 1891 | Frost | 140/92.
|
1763179 | Jun., 1930 | Pierce | 245/1.
|
Foreign Patent Documents |
0032736 | Jul., 1981 | EP.
| |
2133673 | Jan., 1973 | DE.
| |
2234224 | Jan., 1975 | FR.
| |
Primary Examiner: Larson; Lowell A.
Attorney, Agent or Firm: Ruf; Ernst H.
Claims
What is claimed is:
1. A process for manufacturing an automotive tire bead of the type having a
substantially circular-section annular element consisting of a number of
coils packed according to a predetermined program or sequence and formed
from a portion of a bare wire, and having a portion of an outer flexible
packing member which forms a loop wound about said annular element; said
process comprises the steps of:
a) forming said annular element by coiling said portion of the bare wire in
the form of a circle;
b) providing a helical duct extending about substantially the whole of said
annular element, said duct having an inlet and an outlet facing each
other, and a slot extending along an inner generating line of said duct
and facing said annular element;
c) feeding a first end of said portion of said outer flexible packing
member into said duct inlet;
d) blowing said first end along said duct and out through said outlet of
the duct; and
e) connecting said first end to a second end of said portion of said
flexible packing member projecting from said inlet of the duct, so as to
form said loop.
2. A process as defined in claim 1 in which the first end of the flexible
packing member is blown along said duct by a jet of compressed air fed
into said duct through said inlet.
3. An apparatus for manufacturing an automotive tire bead of the type
having a substantially circular-section annular element consisting of a
number of coils packed according to a predetermined program or sequence
and formed from a portion of a bare wire, and having a portion of an outer
flexible packing member with opposite ends forming a loop which is wound
about said annular element; said apparatus comprises a mandrel defining
both an annular seat for winding said portion of said bare wire, and a
duct extending helically about said annular seat terminating in an inlet
and an outlet, and having a slot extending between said inlet and said
outlet providing communication between said duct and said annular seat;
supply means for feeding a jet of compressed air into said duct through
said inlet; and connecting means for joining the opposite ends of said
portion of said flexible packing member to form said loop.
4. An apparatus as defined in claim 3 in which the mandrel comprises an
inner ring having a cylindrical outer surface with a first annular groove
and an outer ring having a cylindrical inner surface contacting said
cylindrical outer surface and having a second annular groove facing said
first annular groove so as to define therewith said annular seat.
5. An apparatus as defined in claim 4 in which the duct extends through
said inner ring and said outer ring; and in which said outer ring presents
an annular opening, with said inlet and said outlet being formed on said
outer ring at said annular opening.
6. An apparatus as defined in claim 5 in which the outer ring comprises
three adjacent segments each moving both axially and radially in relation
to one another and to said inner ring.
7. An apparatus as defined in claim 6 in which the inner ring comprises two
mating annular bodies designed to move axially in relation to each other,
and each bearing a respective portion of said first annular groove.
8. An apparatus as defined in claim 7 including means for continuously
feeding said flexible packing member into said inlet.
9. An apparatus as defined in claim 8 in which the connecting means
comprises a knotting device for both detaching said portion from said
flexible packing member, and for knotting said opposite ends of said
portion.
10. An apparatus as defined in claim 4 in which the outer ring comprises
three adjacent segments each moving both axially and radially in relation
to one another and to said inner ring.
11. An apparatus as defined in claim 10 in which the inner ring comprises
two mating annular bodies designed to move axially in relation to each
other, and each bearing a respective portion of said first annular groove.
12. An apparatus as defined in claim 10 including means for continuously
feeding said flexible packing member into said inlet.
13. An apparatus as defined in claim 10 in which said connecting means
comprises a knotting device for both detaching said portion from said
flexible packing member, and for knotting said opposite ends of said
portion.
Description
TECHNICAL FIELD
The present invention relates to a process for manufacturing an automotive
tire bead.
BACKGROUND OF THE ART
In particular, the present invention relates to a process for manufacturing
a bead as described and claimed in Italian Patent Application No
68169/A-89 filed concurrently with the present Application, the content of
which is fully incorporated herein by reference, and which relates to an
automotive tire bead consisting of a substantially circular-section
annular element formed from a continuous metal wire wound in such a manner
as to form a number of packed coils. Said coils are arranged over the
substantially circular section of said annular element according to a
predetermined law, program or sequence and are held together by an outer
flexible packing member of heat-shrinkable material coiled or wound about
said annular element and the opposite ends of which are connected
together.
DISCLOSURE OF THE INVENTION
According to the present invention, there is provided a process for
manufacturing an automotive tire bead comprising a substantially
circular-section annular element consisting of a number of coils packed
according to a predetermined law, program or sequence and formed from a
portion of a first bare wire; and a portion of a flexible packing member
forming a loop and wound about said annular element; said process being
characterized by the fact that it comprises stages consisting in:
a) forming said annular element by coiling said portion of said wire in the
form of a circle;
b) defining a duct coiling about substantially the whole of said annular
element, and having an inlet and an outlet facing each other, and a slot
extending along an inner generating line of said duct and facing said
annular element;
c) feeding a first end of said portion of said flexible packing member into
said inlet;
d) blowing said first end along said duct and out through said outlet;
e) connecting said first end to a second end of said portion of said
flexible packing member projecting from said inlet, so as to form said
loop.
According to the present invention, there is also provided an apparatus for
manufacturing an automotive tire bead comprising a substantially
circular-section annular element consisting of a number of coils packed
according to a predetermined program or sequence and formed from a portion
of a bare wire; and a portion of a flexible packing member forming a loop
and wound about said annular element; said apparatus being characterized
by the fact that it comprises a mandrel defining both an annular seat for
winding said portion of said first wire, and a duct coiling about said
annular seat and presenting an inlet, an outlet, and a longitudinal slot
extending between said inlet and said outlet for enabling communication
between said duct and said annular seat; supply means for feeding a jet of
compressed air into said duct through said inlet; and connecting means for
joining the two opposite ends of said portion of said flexible packing
member and so forming said loop.
A non-limiting embodiment of the present invention will now be described by
way of example with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial view, in perspective, of a preferred embodiment of
the bead formed using the process and apparatus according to the present
invention;
FIG. 2 shows a diagram of the process for forming the FIG. 1 bead according
to the present invention;
FIG. 3 shows a partial exploded view, in perspective, of a preferred
embodiment of the apparatus according to the present invention, for
producing the FIG. 1 bead according to the FIG. 2 process;
FIGS. 4, 5 and 6 show larger-scale, partial radial sections of the FIG. 3
apparatus in three successive operating positions;
FIG. 7 shows a view, in perspective, of the FIG. 3 apparatus at a further
operating stage;
FIG. 8 shows an exploded version of FIG. 7, illustrating the FIG. 3
apparatus at yet a further operating stage;
FIG. 9 shows a similar section to that of FIGS. 4 to 6, illustrating the
FIG. 3 apparatus at the final operating stage.
BEST MODE FOR CARRYING OUT THE INVENTION
Number 1 in FIG. 1 indicates a "program" bead for an automotive tire,
consisting of a substantially circular-section annular element 2 formed
from a continuous bare metal wire 3 wound in such a manner as to form a
number of packed coils 4 (FIG. 4). Wire 3 may consist of a solid metal
wire preferably, but not necessarily, of circular section, or, preferably,
as in the example shown, of a metal cable.
Coils 4 are held together by a portion of an outer flexible packing member
5 of heat-shrinkable material, e.g., polyamide, wound about annular
element 2 and having two opposite ends 6 tied in a knot 7. The sections of
coils 4 are arranged over the circular section of annular element 2
according to a predetermined law, sequence or "program". As shown more
clearly, for example, in FIG. 4, said coils 4 are arranged in a number of
superimposed layers 8, each of the intermediate layers of which comprises
a greater number of coils 4 than in outer layers 8, so as to form said
substantially circular section of annular element 2.
As shown schematically in FIG. 2, the process for forming bead 1 comprises
stages consisting in forming annular element 2, on which is subsequently
defined a duct 9 coiling about and extending over substantially the entire
length of annular element 2. Duct 9 presents, along an inner generating
line, a helical slot 10 facing the outer surface of annular element 2, and
an interruption defining an inlet 11 and an outlet 12. The end of a
continuous flexible packing member 13, preferably fed off a reel 14, is
then fed through inlet 11 and "shot" into duct 9 by a jet of compressed
air supplied by a nozzle 15 facing inlet 11. By virtue of said jet, the
end of member 13 is fed along duct 9 and out through outlet 12. At this
point, the compressed air supply from nozzle 15 is cut off and a known
type of knotting device 16 activated for cutting member 13 to size and so
forming said flexible packing member portion 5. At the same time, said
knotting device 16 engages ends 6 of portion 5 for tying knot 7 while at
the same time withdrawing portion 5 through slot 10 and onto the outer
surface of annular element 2.
It should be pointed out, in connection with the above, that knotting
device 16 may be of any known type, which provides solely for bringing
portion 5 into contact with the outer surface of annular element 2, but
not for applying a given tension to the same. Consequently, once knot 7 is
tied, the tension of flexible packing member portion 5 is substantially
zero, and barely sufficient to ensure a stable shape of annular element 2,
but not to prevent mutual axial and transverse displacement of coils 4
when annular element 2 is twisted. When curing the finished green tire,
however, the heat applied causes flexible packing member portion 5 to
shrink tightly about and so pack coils 4. Knotting device 16 may, of
course, be replaced by any other suitable device, e.g. a welder or
splicer, for joining ends 6 in knot-free manner.
FIGS. 3 and 4 to 8 show an apparatus consisting of a mandrel 17 enabling
implementation of the process for fabricating bead 1 a described with
reference to FIG. 2. As shown particularly in FIGS. 3 and 8, mandrel 17
comprises an inner ring 18 defined externally by a cylindrical surface 19,
and an outer ring 20 defined internally by a cylindrical surface 21 mating
with surface 19. Inner ring 18 consists of two mirror-image annular bodies
22 and 23, identical to each other in relation to the central plane of
ring 18 perpendicular to the axis of the same, and along which said two
annular bodies 22 and 23 are arranged contacting each other along
respective flat annular surfaces 24 and 25. According to a variation not
shown, the inner edges of surfaces 24 and 25 present mating tapered
surfaces for ensuring correct mutual positioning of annular bodies 22 and
23.
Along surface 19 there is formed an annular groove 26 having a
substantially semicircular section and the diametrical plane of which
coincides with the plane of surfaces 24 and 25. In other words, a first
transverse half 27 (FIG. 3) of groove 26 (FIG. 5) is formed in annular
body 22, while the second half 28 (FIG. 3) is formed in annular body 23.
Outer ring 20 consists of three consecutive segments 29, 30 and 31.
Intermediate segment 29 extends over an arc of approximately 120.degree.,
whereas sectors 30 and 31 extend over respective slightly narrower arcs
(FIG. 7) so as to present two facing end surfaces 32 and 33 defining an
annular break or opening 34. Cylindrical surface 21 of ring 20 presents an
annular groove 35 having a substantially semicircular section and
interrupted at opening 34. When rings 18 and 20 are placed together,
grooves 26 and 35 define an annular eat 36 (FIG. 6) of substantially
circular section, communicating externally via opening 34 and housing
annular element 2. Duct 9 in FIG. 2 is formed along mandrel 17, together
with slot 10, in such a manner as to coil about seat 36, and comprises a
number of duct segments 37 formed in annular body 22, a number of segments
38 formed in annular body 23, and a number of segments 39 formed in each
of segments 29, 30 and 31 of outer ring 20. In particular, two of said
segments 39 terminate at respective surfaces 31 and 30, so as to define
inlet 11 and outlet 12 of duct 9.
Formation of bead 1 on mandrel 17 will be described with reference to FIGS.
4 to 9. As shown in FIG. 4, to begin with, annular bodies 22 and 23 are
placed together so as to define inner ring 18 together with respective
groove 26. Inner ring 18 is preferably mounted on a rotary support (not
shown) designed to turn ring 18 about its axis, and on which annular body
22 is fitted in a substantially fixed axial position, while annular body
23 is fitted in such a manner as to move axially in relation to annular
body 22 between a working position (FIGS. 4 to 8) wherein annular surfaces
24 and 25 contact each other, and an unloading position (FIG. 9) wherein
surfaces 24 and 25 are separated by a distance at least equal to the
diameter of groove 26.
Wire 3, normally fed off a reel (not shown), is fed inside groove 26 via a
known prior at feeding device 40 and secured, in any convenient manner,
with one end contacting a given point on the surface of groove 26. Feeding
device 40 is normally controlled by a computer (not shown), and moves back
and forth, as controlled by said computer and according to a given or
predetermined program, in direction 41 parallel to the axis of ring 18, so
as to form, subsequent to rotation of ring 18 about its own axis, a number
of coils 4 (FIG. 4) arranged in a number of layers 8 according to a given
sequence, so as to form annular element 2, the circular section of which
is substantially housed half inside and half projecting outwardly of
groove 26.
As already described with reference to FIG. 2, flexible packing member 13
(FIGS. 6 and 7) is then fed into inlet 11 of duct 9, blown along duct 9
and out through outlet 12, and cut to size and tied by device 16 so as to
define both knot 7 and flexible packing member portion 5 engaged inside
slit 10 and coiled about annular element 2.
Once bead 1 is formed, segments 29, 30 and 31 are moved (FIG. 9) first
radially outwardly in the direction of arrow 45 opposite arrow 44, and
then axially in the direction of arrow 46 opposite arrow 43 back to the
idle position shown in FIG. 4. At the same time, annular body 23 is moved
axially in relation to annular body 22 and in the direction of arrow 47
from the work position contacting annular body 22 to the unloading
position, thus enabling removal of bead 1 from annular body 22.
From the foregoing description and the operational discussion, when read in
light of the several drawings, it is believed that those familiar with the
art will readily recognize and appreciate the novel concepts and features
of the present invention. Obviously, while the invention has been
described in relation to only a limited number of embodiments, numerous
variations, changes, substitutions and equivalents will present themselves
to persons skilled in the art and may be made without necessarily
departing from the scope and principles of this invention. As a result,
the embodiments described herein are subject to various modifications,
changes and the like without departing from the spirit and scope of the
invention with the latter being determined solely by reference to the
claims appended hereto.
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